Multiglazed window unit

ABSTRACT

A multiglazed window having a liquid-sealed venting system effective to normally provide a hermetic seal to the window interior but permitting airflow when the pressure differential between said interior and the surrounding atmosphere exceeds a predetermined value to thereby effectively limit such differential pressure.

United States Patent 44 9 44 SOHO 55 23 2 22 //5/ 72 2 77 35 5 33 m M m n H .W mm m "N H mm mm WW I .e v "S "DAV," .rs n m aw mmMkGm em re .B W ESMC GS O 3785 24 334 22 9999 99 HHHH ll 660 8299 75 320 78 0327 70 5828 56 3 222 .B w mu .m 0 1 s H 07am 79 9 K 9lf 1 98 5m 8 3 52 M0 h.m2 um e CCSJ HP 0 e m N mm m mrdmz i v mm m AFPA l 111]] 2 1253 7 2247 l llll Primary Examiner-John E. Murtagh Altorneys-Carlton F. Bryant, Eldon H. Luther, Robert L. Olson, John F. Carney, Richard H. Berneike, Edward L. Kochey, Jr. and Lawrence P. Kessler 3 T W u N n U w w. m Nm IF W8 m .m m E m m m M m um e C 5 M1 U 4 U s U [51] Int. Fl6k 9/00 ABSTRACT; A mumglazed window having a |iquid-sealed Field of Searchww 52/304 1 venting system effective to normally provide a hermetic seal 137/251-254 to the window interior but permitting airflow when the pres- Reerences Cited sure differential between said interior and the surrounding atmosphere exceeds a predetermined value to thereby effec- UNITED STATES PATENTS tively limit such differential pressure. 3/1872 PATENTEU DEC 2 8197! SHEET 1 OF 2 INVENTOR. Charles K. Herd/s ("an M MULTIGLAZED WINDOW UNIT BACKGROUND OF THE INVENTION The invention is concerned with insulating windows comprised of a plurality of glass sheets that are retained in spaced relation within a suitable frame being sealed in the frame to provide a hermetically sealed chamber therebetween. In certain units of this type, it is necessary to provide some means for preventing the differential pressure between the window interior and the surrounding atmosphere from exceeding a predetermined value. This problem is particularly acute in such windows wherein the spacing between the glass sheets is relatively large so that the deflection of the glass sheets themselves does not sufficiently change the pressure within the sealed chamber to compensate for substantial atmospheric pressure changes. Such is the case in double glazed windows that have the property of not only providing good thermal insulation but also being effective sound insulators. Windows of this type may have the glass sheets spaced from I to 8 inches apart with the normal being 2 to 4 inches apart and with the two sheets normally being of different thickness. For instance, one may be three-fourths inch thick and the other threeeighths inch thick. In such a case the chamber between the glass sheets is large so that flexure of the sheets has only a limited effect on the internal pressure, and furthermore the thinner sheet accommodates almost all of the flexure. Under these conditions severe stresses are built up as a result of atmospheric pressure changes which may cause glass breakage and which may strain the hermetic seal so that it may become defective. Furthermore, such movement of the glass can cause unpleasant convexity or concavity thereof, particularly in a unit made with reflective glass. Accordingly, in order to prevent these disadvantages, it is desired to limit the differential pressure that can be developed between the interior of the window and the surrounding atmosphere. At the same time, it is desired that there not be an unrestricted communication between these regions for the reason that moisture problems may then develop within the window. It is conventional to use desiccants to maintain the air in the window chamber in a dry condition so as to prevent condensation. However, the desiccant may become ineffective for this purpose if there is free communication between the window interior and the surrounding atmosphere.

BRIEF DESCRIPTION OF THE INVENTION In accordance with the present invention there is provided a venting system effective to automatically control communication between the sealed air chamber of the insulating window and the surrounding atmosphere. The system responds to the differential pressure between this chamber and the atmosphere with the system being effective to normally prevent such communication; but when the difierential pressure exceeds a predetermined value, it will be effective to bleed air into or from the chamber so as to reduce such pressure differential below this value. The venting system is controlled by means of a liquid seal control element with this element being in a form to have one portion communicate with the interior chamber and another portion communicating with atmosphere and normally sealed by a liquid sealant from establishing communication with and through said one portion.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view partially broken away showing a multiple glazed insulated window with one form of the improved venting system attached thereto;

FIGS. 2 through 5 illustrate the operating sequence of the liquid seal that forms a part of the venting system of FIG. 1 and shows the disposition of the sealant in the U-tube in various positions resulting from pressure differential;

FIG. 6 is a detailed view of the lower portion of the U-tube sealing member;

FIG. 7 is a sectional view taken along line 7-7 of FIG. 6;

FIG. 8 is a view partially in section showing a modified form of venting system for use with the invention; and

FIG. 9 is a partial sectional view of still another embodiment of the improved venting system of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS Referring now to the drawings wherein like reference numerals are used throughout to designate like elements, the illustrative embodiment of the invention depicted in FIGS. 1 through 7 comprises a double glazed window unit including spaced glass sheets 10 and 12 retained in a suitable frame 14 in a manner such as to provide a hermetic seal about the periphery of the glass sheets. As disclosed, sheet 10 is received with channel I6 and sheet 14 in channel 18 of the frame with suitable sealant being provided in these channels to effect the desired seal. The space intermediate the glass sheets, i.e., chamber 20, is filled with relatively dry air and in order that the moisture content of the air in this chamber remain relatively low, there may be provided in the channel 22 of frame 14 a suitable desiccant such as silica gel or the like.

In order that the difference in pressure between chamber 20 and the surrounding atmosphere will be limited to a predetermined value while at the same time there will not be continuous open communication therebetween, there is provided a control venting system for chamber 20 which includes the conduit 24 that extends through the frame 14 in sealing relation with the frame and is connected to the upper end of leg 26 of U-tube 28. The other leg, i.e., leg 32 of the U-tube, is in communication with the atmosphere. The U-tube has disposed therein a suitable sealing liquid 34 so as to respond to the pressure difference between chamber 20 and the surrounding atmosphere and to bleed air into or out of the chamber when this pressure difference exceeds a desired value. FIGS. 2, 3, 4 and 5 illustrate the action of the sealing liquid when the pressure in chamber 20 builds up beyond a desired value relative to the atmospheric pressure. In FIG. 2 the level in each of the legs 26 and 32 is the same such that the pressure in chamber 20 and the surrounding atmosphere is generally the same. As the pressure in chamber 20 rises relative to that of the atmosphere, the liquid is moved to the position indicated in FIG. 3. Here the liquid is still effective to prevent communication of chamber 20 with the atmosphere notwithstanding that a pressure difference exists therebetween. FIG. 4 illustrates the condition where the pressure difference has risen to a sufficiently high value as to bleed air from chamber 20 with the air bubbling through the sealing liquid 34 and out the leg 32 of the U-tube. FIG. 5 illustrates the position of the sealing liquid after thus bleeding excess air from chamber 20 to lower the pressure to a value such that the liquid will again seal the vent.

There is preferably provided in each of the legs 26 and 32 a filter plug 38 which may be of any desired material which will permit the passage of air therethrough such as Fiberglas or the like with the material in leg 26 preventing mercury from being splashed over into the chamber 20 during shipment as well as during the admission of air during normal operation of the liquid seal in the vent. The filter in leg 32 prevents loss of mercury from this leg during shipping as well as preventing foreign material from collecting on the upper surface of the sealing liquid.

The sealing liquid 34 may be any, preferably nonvolatile, liquid which will provide .satisfactory operation. In instances where the liquid seal member is located so that access is difficult, it is desired that the liquid be capable of satisfactory performance for many years. Mercury is quite suitable for this purpose.

In order that the U-tube may be of small diameter and still permit air to bubble upwardly through the liquid in either of the legs, it is desired that the inner region of the bend and the legs of the U-tube not conform to a circular cross section but rather have a distended portion 36 as shown in FIG. 7 so as to, in effect, form an outwardly disposed groove. Moreover, any

cross section which deviates from the circular but does not have sharply angled comers would be advantageous. Thus an ovoidal or pear-shaped cross section can be employed. These noncircular cross sections will utilize the cohesiveness and nonwetting characteristics of a mercury sealant in glass or plastic to provide a preferred air path. Air will tend to flow through the narrow or constricted portion of the tube while the mercury remains in the portion of larger radius. This will minimize spatter of the mercury sealant when it bubbles and permit miniaturization of the device.

It is noted that in the illustrative embodiment U-tube 28 is mounted on the exterior of frame 14. The U-tube 28 may be secured in place in any desired manner such as by suitable adhesives, sealants, or the like or mechanical clamps. One advantage of the invention is that the U-tube may be mounted where desired. It may be mounted on the inside of the frame rather than the outside, or it may be mounted remote from the window being connected with the window through suitable tubing, It is further noted that the leg of the U-tube which communicates with atmosphere may effect this communication through a suitable desiccant, if desired, so that only dry air is supplied to the window interior. This desiccant may be in addition to or in lieu of desiccant in channel 22 of frame 14. It is also to be noted that by means of the U-tube it is very easy to adjust the sealing system so that it will respond to any desired pressure differential or in other words, control the pressure within chamber 14 to any desired differential with respect to the atmosphere. This can be done by varying the amount of liquid sealant in the U-tube 28.

In the embodiment of FIG. 8, there is provided, in lieu of the U-tube arrangement previously described, a sealing member that is in the form of a conventional bubbler including the vessel 40 into which extends the tube member 42 such that its lower end normally terminates below the level of the liquid sealant 34 in the vessel. Tube member 42 is provided with the enlarged region 44 located within the vessel 40 for receipt of the sealing liquid during operation. In this FIG. 8 embodiment, the sealing member is disclosed as located remotely from the window frame being secured to a portion of the building structure into which the window is mounted with this portion being identified as 46. The outlet 48 of vessel 40 communicates with the chamber 20 of the window by means of the flexible tube 50. The upper end of tube member 42 communicates with atmosphere, and the sealing member functions to normally prevent communication between the window interior and atmosphere but to permit the flow of air in either direction incident to the pressure differential reaching a predetermined value as in the case of the FIGS. 1 through 7 embodiment.

ln HO. 9 there is disclosed a still further modified arrangement wherein two tubes 52 and 54 are mounted with a vessel 56 such that their lower ends normally extend below the level of the liquid sealant 34 in the vessel. In this embodiment each of the tubes is provided with an enlarged region as shown for receipt of the sealing liquid during operation and tube 52 communicates with atmosphere at its upper end while tube 54 extends through frame 14 in sealing relation therewith and communicates with the chamber 20 of the window. This arrangement provides for a larger body of sealing fluid and, accordingly, minimizes any problem that may be encountered in connection with contamination of the fluid. As shown, the sealing member is mounted on the exterior of the frame although it will be understood as in the case of the other embodiments, that it may be at any location desired.

Filter plugs 38 are also preferably provided with the embodiments of FlGS. 8 and 9.

it will thus be seen that the present invention solves the problem relative to developing of excessive stresses in the glass and the sealing frame of multiglazed windows and at the same time prevents the free and uncontrolled admission of air and accordingly moisture in the window interior space.

It will be understood that various changes in the details, materials, and arrangements of parts which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

What is claimed is:

1. A multiglazed window comprising at least a pair of glass sheets secured by frame means in spaced relation to define a hermetically sealed air chamber therebetween, said frame means having normally vertical side members, means effective to limit the pressure differential between said chamber and the surrounding atmosphere to a predetermined value comprising vent means having liquid seal means associated therewith operative to normally close said vent means but responsive to such pressure differential to permit the passage of air therebetween, said seal means including a vessel mounted on one of the vertical side members of the frame and having a pool of liquid sealant therein, a pair of tube members extending down into said liquid with their lower ends normally below the sealant level, each of said members having enlarged portions intermediate their extremities and normally disposed somewhat above the sealant level, one of said tube members communicating with atmosphere and the other communicating with said sealed air chamber, and a filter plug in each of said members permitting passage of air but restricting passage of foreign material. 

1. A multiglazed window comprising at least a pair of glass sheets secured by frame means in spaced relation to define a hermetically sealed air chamber therebetween, said frame means having normally vertical side members, means effective to limit the pressure differential between said chamber and the surrounding atmosphere to a predetermined value comprising vent means having liquid seal means associated therewith operative to normally close said vent means but responsive to such pressure differential to permit the passage of air therebetween, said seal means including a vessel mounted on one of the vertical side members of the frame and having a pool of liquid sealant therein, a pair of tube members extending down into said liquid with their lower ends normally below the sealant level, each of said members having enlarged portions intermediate their extremities and normally disposed somewhat above the sealant level, one of said tube members communicating with atmosphere and the other communicating with said sealed air chamber, and a filter plug in each of said members permitting passage of air but restricting passage of foreign material. 